Musical instruments have always been very popular in society—providing entertainment, social interaction, self-expression, and a business and source of livelihood for many people. String instruments are especially popular because of their active playability, tonal properties, and portability. String instruments are fun and yet challenging to play and have great sound qualities.
Guitars are one type of string musical instrument. The musical artist, or user, plays the guitar by using his or her fingers, or a guitar pick, to displace one or more of the tightly-strung strings from a neutral position and then releasing it, causing the string to vibrate as it returns to its neutral position. The vibrating string produces the desired sound. The guitar pick offers certain advantages over the fingers in terms of sharpness of the string vibration and clarity of the note played.
In the case of electric guitars, the string vibration is sensed by electromagnetic pickups which detect the string movement in an electric field and produce electrical signals representative of the string movement. The electric signals are routed to an external amplifier and speaker system which produces the sound.
The external equipment may contain one or more electronic circuits for modifying or enhancing the sound. For example, an effects processor can be used to enhance and adjust the acoustic qualities for the instrument. Other electronic circuits can provide filtering, synthesis, signal conditioning, signal distribution, signal conversion, and signal processing.
The external signal processing is typically built into the individual equipment and not readily transferable between systems. Each type of external equipment is dedicated for its intended function, e.g., the amplifier performs amplification, the effects module controls effects, and the synthesizer generates sounds. Yet, while each type of external equipment performs the specific function each was designed for, none provide the flexibility or convenience in moving signal processing capability between systems. The dedicated design of each type of external equipment increases capital costs, reduces system integration, and in some cases duplicates features.